As the first milestone in the development of high-resolution targeted CT scans (zoom CT) in patients, we constructed a version of zoom CT in a clinical CT scanner in collaboration with Drs. Marcus Chen. It has been used in 180 patients of Dr. Joel Moss's lymphangioleiomyomatosis protocol to study in detail the morphology of the lung cysts in these patients, and accurately measure the volume of the lungs occupied by cysts. The LAM patient study has produced 3 abstract presentations at the American Thoracic Society 2019 meeting in Dallas. It has been tested in the first several patients with the rare disease arterial calcification due to deficiency of CD73, to visualize micro-calcification in the border zones of the affected arteries and precisely measure progression/regression of calcification in these border zones. Both studies are on-going. In collaboration with the Clinical Center Radiology Department, we are working to construct a zoom CT protocol on a clinical scanner in Radiology in response to their request for this technology, for the purpose of precise staging of bladder cancer. This work is at the initial phantom optimization and dose estimation stage. In collaboration with Varex/Direct Conversion GmBH, we are developing the next generation of the zoom CT hardware to more than double the resolution and reduce the radiation dose to be equivalent to x-ray radiography. We have built a tabletop x-ray optical sectioning microscope, a third generation of a technology that began development in our lab in 2017. This microscope provides a significant leap in image quality in a 15 minute scan when compared to a 3 hour scan on a commercial micro-CT scanner. In collaboration with Drs. Ahmed Gharib, Alan Remaley and Manfred Boehm, the microscope was used to detect an initiation stage of Monckeberg's medial sclerosis in human coronary artery specimens. In collaboration with Dr. Joel Moss and Dr. Zu-Xi Yu it is being used to characterize and guide histopathology of lung biopsy specimens. In collaboration with Dr. Beth Kozel it is being used to characterize abnormalities of blood vessels in the brain of genetic mouse models. In collaboration with Dr. Chiffon Yang and Alan Remaley it is being used to detect and quantify calcification in mouse heart and aorta samples. In parallel to the applications, software algorithms are continually being developed to speed up the image reconstruction time and quality. A ten-fold improvement of image reconstruction speed has been achieved in the past year.